LUTEOTROPHIC ACTIONS OF INSULIN-LIKE GROWTH FACTOR-I

黄体是产生黄体酮的卵巢结构。 维持妊娠所必需的激素。语料库 黄体在荷尔蒙或因素的刺激下产生孕酮，称为 黄体生成素。在兔子体内，主要的促黄体激素是雌激素， 由卵泡产生。从初步研究和其他 信息，我们对黄体营养过程提出了一个新的概念 兔：雌激素刺激胰岛素样生长因子-I的产生 和/或胰岛素样生长因子-II(IGF-I/IGF-II)，以及 然后，IGF-I/IGF-II以自分泌或旁分泌的方式刺激 黄体细胞的代谢和类固醇合成。为了检验这一假设， 我们将使用几种方法，每种方法都具有特定的优势 操纵黄体营养环境：从雌激素获得的黄体组织- 处理动物，正常假孕和妊娠兔； 器官培养中的黄体组织；单层培养中的黄体细胞 这种类固醇的生成由IGF-I显著维持。使用这些 方法，将进行实验以确定：a)IGF-I 和/或IGF-II及其受体和IGF-I的mRNA在 光镜显示黄体的特殊细胞类型-和 电子显微镜免疫细胞化学和原位杂交； 这种表达是否随着雌激素的刺激而变化，以及在不同的 用计算机确定黄体期和妊娠期 图像分析和定量形态计量学；b)IGF-I是否与类型结合 I型或II型受体，以及这些受体是否可以被 雌激素，并在假孕和假孕不同阶段的变化 妊娠；c)IGF-I/IGF-II是否通过产生 黄体细胞的胰岛素样代谢作用；d)类固醇的生成 可归因于黄体组织的自分泌/旁分泌作用 IGF-I/IGF-II。

The corpus luteum is the ovarian structure that produces progesterone, a hormone that is essential for the maintenance of pregnancy. The corpus luteum is stimulated to produce progesterone by hormones or factors, called luteotrophins. In the rabbit, the principal luteotrophin is estrogen, produced by the ovarian follicles. From preliminary studies and other information, we propose a new concept for the luteotrophic process in the rabbit: estrogen stimulates the production of insulin-like growth factor-I and/or insulin-like growth factor-II (IGF-I/IGF-II) by luteal cells, and IGF-I/IGF-II then acts in an autocrine or paracrine manner to stimulate metabolism and steroidogenesis by luteal cells. To test this hypothesis, we will use several approaches, each with particular advantage to manipulate the luteotrophic milieu: luteal tissue obtained from estrogen- treated animals, and from normal pseudopregnant and pregnant rabbits; luteal tissue in organ culture; and luteal cells in monolayer culture, in which steroidogenesis is strikingly maintained by IGF-I. Using these approaches, experiments will be conducted to determine: a) whether IGF-I and/or IGF-II, their receptors, and mRNA for IGF-I are expressed in specific cell types of the corpus luteum as revealed by light - and electron - microscopic immunocytochemistry and in situ hybridization; and whether this expression changes with estrogen stimulation and in different stages of the luteal phase and pregnancy as determined by computer-based image analysis and quantitative morphometry; b) whether IGF-I binds to type I or type II receptors, and whether these receptors can be regulated by estrogen, and change during different stages of pseudopregnancy and pregnancy; c) whether IGF-I/IGF-II has a trophic action by producing insulin-like metabolic effects in luteal cells; d) whether steroidogenesis by rabbit luteal tissue is attributable to an autocrine/paracrine action of IGF-I/IGF-II.